1. The Nature of Covalent Bonding

2. Covalent Compounds 2 nonmetals form a bond
Electrons are shared to form the noble gas configuration
Ex: H2

3. Drawing Covalent Molecules
In order to do this you need to know what a Lewis Dot Diagram is!!!!
Lewis Dot Diagram- Write the chemical symbol for the element and use dots to represent valence electrons.
Ex: Mg:
Remember: there is a maximum of 8 dots that you can draw…can you think why?

4. Single Bonds
Single Covalent Bond- 2 atoms held together by sharing one pair of electrons.
Example: H:H or H-H
The dash represents the single bond

5. Structural Formula- represents covalent bonds by dashes and shows the arrangement of covalently bonded atoms.
Example: F2
* NOTE: ALL HALOGENS ARE DIATOMIC MOLECULES!!!*

6. The Shapes of Molecules
VSEPR – valence shell electron pair repulsion model
Provides a way to predict the shapes of molecules
This is determined by drawing a dot diagram for the molecule

7. Electron Pairs have 2 types
Shared Pairs- pair of electrons in a covalent bond (dashed line)
Lone Pairs- pair of valence electrons that is not shared between atoms, called lone pair or non-bonding pair(dots)

8. Example #1: H2O
Lewis Dot Structure:
Structural Formula:

9. Example #2: NH3
Lewis Dot Structure:
Structural Formula:

10. Example #3: CH4
Lewis Dot Structure:
Structural Formula:

11. Double & Triple Covalent Bonds
Double covalent bond- a bond that there are 2 shared pairs of electrons (4 electrons)
Ex: O2
Triple covalent bond- a bond that there are 3 shared pairs of electrons (6 electrons).
Ex: N2

12. Stability
The more shared pairs it has…the MORE STABLE THE MOLECULE!

13. What type of bonds do these form?
1. CO2
2. HCN
3. Br2